Currently, 119 high resolution structures of
Thermotoga maritima proteins have been determined by the Joint Center for Structural Genomics (JCSG, www.jcsg.org). Sixty-seven of these were
solved using the first implementation of the multi-tiered crystallization strategy at the JCSG for the efficient crystallization
of large numbers of protein targets. Previously, we reported the analysis of all proteins crystallized using this multi-tiered
strategy [Lesley, S.A. et al. (2002)
Proc. Natl. Acad. Sci. USA 99, 11664–11669; Page, R. et al. (2003)
Acta Crystallogr. D Biol. Crystallogr.
59, 1028–1037]. Here, we extend the analysis and describe the crystallization characteristics of those proteins that produced
diffraction quality crystals, ultimately resulting in high resolution structures. First, we found that over 77% (52) of the
crystals used for structure determination were produced directly from high-throughput coarse screens, indicating that less
than one quarter of the crystals (15) required fine screening. In addition, as observed for the proteome screen [Page, R.
et al. (2003)
Acta Crystallogr. D Biol. Crystallogr.
59, 1028–1037], the majority of conditions that produced crystals for natively expressed proteins, whose structures have been
determined, were distinct from those of their more extensively purified and selenomethionine-labeled counterparts. Finally,
99% of the proteins whose structures were solved crystallized in conditions contained in the JCSG Minimal Core Screen [Page,
R. et al. (2003)
Acta Crystallogr. D Biol. Crystallogr.
59, 1028–1037; Page, R. and Stevens, R.C. (2004)
Methods 34, 373–389], a set of 67 conditions previously identified as those most likely to produce crystals of a diverse set of proteins,
confirming its success for rapid identification of proteins with a natural propensity to crystallize.
Key words crystallization - structures - structural genomics